Threlkeld was last seen leaving on foot from a library in Silver Creek, New York. Her brother saw her walking on the road home and offered her a ride which she declined saying she wanted to walk. Threlkeld was never seen again, and has had no contact with her family or friends in 46 years. It has been noted that right before she disappeared a witness saw a dump truck in the area and it was operated by a man in his mid 20s who had a beard and sandy blond hair.  To date, the police have never been able to get in contact with this individual. She was last seen wearing blue jeans, khaki shirt, blue sweater, navy blue suede coat, brown purse, snow boots